Toxics

Research

13 pages, 2493 KiB

Open AccessArticle

Impact of COVID-19 Lockdown on Oxidative Potential of Particulate Matter: Case of Athens (Greece)

by Despina Paraskevopoulou, Aikaterini Bougiatioti, Pavlos Zarmpas, Maria Tsagkaraki, Athanasios Nenes and Nikolaos Mihalopoulos

Toxics 2022, 10(6), 280; https://doi.org/10.3390/toxics10060280 - 25 May 2022

Cited by 6 | Viewed by 2549

Abstract

This work evaluates the aerosol oxidative potential (OP) and its changes from modified air pollution emissions during the COVID-19 lockdown period in 2020, with the intent of elucidating the contribution of aerosol sources and related components to aerosol OP. For this, daily particulate [...] Read more.

This work evaluates the aerosol oxidative potential (OP) and its changes from modified air pollution emissions during the COVID-19 lockdown period in 2020, with the intent of elucidating the contribution of aerosol sources and related components to aerosol OP. For this, daily particulate matter (PM) samples at an urban background site were collected and analyzed with a chemical (acellular) assay based on Dithiothreitol (DTT) during the COVID-19 restriction period in Athens (Greece). The obtained time-series of OP, PM_2.5, organic matter (OM) and SO₄²⁻ of the pre-, post- and lockdown periods were also compared to the data of the same time periods during the years 2017–2019. Even though all traffic-related emissions have been significantly reduced during the lockdown period (by 30%), there is no reduction in water-soluble OP, organics and sulfate concentrations of aerosol during 2020. The results reveal that the decrease in traffic was not sufficient to drive any measurable change on OP, suggesting that other sources—such as biomass burning and secondary aerosol from long-range transport, which remained unchanged during the COVID lockdown—are the main contributors to OP in Athens, Greece. Full article

(This article belongs to the Special Issue Innovative Air Pollution Measurements, Characterization and Source Apportionment)

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16 pages, 1677 KiB

Open AccessArticle

Synergistic and Antagonistic Effects of Aerosol Components on Its Oxidative Potential as Predictor of Particle Toxicity

by Maria Chiara Pietrogrande, Luisa Romanato and Mara Russo

Toxics 2022, 10(4), 196; https://doi.org/10.3390/toxics10040196 - 16 Apr 2022

Cited by 14 | Viewed by 3387

Abstract

Quantifying the component-specific contribution to the oxidative potential (OP) of ambient particle matter (PM) is the key information to properly representing its acute health hazards. In this study, we investigated the interactions between the major contributors to OP, i.e., transition metals and quinones, [...] Read more.

Quantifying the component-specific contribution to the oxidative potential (OP) of ambient particle matter (PM) is the key information to properly representing its acute health hazards. In this study, we investigated the interactions between the major contributors to OP, i.e., transition metals and quinones, to highlight the relative effects of these species to the total OP. Several synergistic and antagonistic interactions were found that significantly change the redox properties of their binary mixtures, increasing or decreasing the values computed by a simple additive model. Such results from the standard solutions were confirmed by extending the study to atmospheric PM_2.5 samples collected in winter in the Lombardia region, a hot spot for air pollution in northern Italy. This work highlights that a solid estimation of oxidative properties of ambient PM requires an interaction-based approach accounting for the interaction effects between metals and quinones. Full article

(This article belongs to the Special Issue Innovative Air Pollution Measurements, Characterization and Source Apportionment)

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21 pages, 1394 KiB

Open AccessArticle

Detailed Speciation of Non-Methane Volatile Organic Compounds in Exhaust Emissions from Diesel and Gasoline Euro 5 Vehicles Using Online and Offline Measurements

by Baptiste Marques, Evangelia Kostenidou, Alvaro Martinez Valiente, Boris Vansevenant, Thibaud Sarica, Ludovic Fine, Brice Temime-Roussel, Patrick Tassel, Pascal Perret, Yao Liu, Karine Sartelet, Corinne Ferronato and Barbara D’Anna

Toxics 2022, 10(4), 184; https://doi.org/10.3390/toxics10040184 - 8 Apr 2022

Cited by 13 | Viewed by 4185

Abstract

The characterization of vehicle exhaust emissions of volatile organic compounds (VOCs) is essential to estimate their impact on the formation of secondary organic aerosol (SOA) and, more generally, air quality. This paper revises and updates non-methane volatile organic compounds (NMVOCs) tailpipe emissions of [...] Read more.

The characterization of vehicle exhaust emissions of volatile organic compounds (VOCs) is essential to estimate their impact on the formation of secondary organic aerosol (SOA) and, more generally, air quality. This paper revises and updates non-methane volatile organic compounds (NMVOCs) tailpipe emissions of three Euro 5 vehicles during Artemis cold urban (CU) and motorway (MW) cycles. Positive matrix factorization (PMF) analysis is carried out for the first time on proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) datasets of vehicular emission. Statistical analysis helped to associate the emitted VOCs to specific driving conditions, such as the start of the vehicles, the activation of the catalysts, or to specific engine combustion regimes. Merged PTR-ToF-MS and automated thermal desorption gas chromatography mass spectrometer (ATD-GC-MS) datasets provided an exhaustive description of the NMVOC emission factors (EFs) of the vehicles, thus helping to identify and quantify up to 147 individual compounds. In general, emissions during the CU cycle exceed those during the MW cycle. The gasoline direct injection (GDI) vehicle exhibits the highest EF during both CU and MW cycles (252 and 15 mg/km), followed by the port-fuel injection (PFI) vehicle (24 and 0.4 mg/km), and finally the diesel vehicle (15 and 3 mg/km). For all vehicles, emissions are dominated by unburnt fuel and incomplete combustion products. Diesel emissions are mostly represented by oxygenated compounds (65%) and aliphatic hydrocarbons (23%) up to C₂₂, while GDI and PFI exhaust emissions are composed of monoaromatics (68%) and alkanes (15%). Intermediate volatility organic compounds (IVOCs) range from 2.7 to 13% of the emissions, comprising essentially linear alkanes for the diesel vehicle, while naphthalene accounts up to 42% of the IVOC fraction for the gasoline vehicles. This work demonstrates that PMF analysis of PTR-ToF-MS datasets and GC-MS analysis of vehicular emissions provide a revised and deep characterization of vehicular emissions to enrich current emission inventories. Full article

(This article belongs to the Special Issue Innovative Air Pollution Measurements, Characterization and Source Apportionment)

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27 pages, 6272 KiB

Open AccessFeature PaperArticle

Using Real Time Measurements to Derive the Indoor and Outdoor Contributions of Submicron Particulate Species and Trace Gases

by Evdokia Stratigou, Sébastien Dusanter, Joel Brito, Emmanuel Tison and Véronique Riffault

Toxics 2022, 10(4), 161; https://doi.org/10.3390/toxics10040161 - 29 Mar 2022

Cited by 6 | Viewed by 2746

Abstract

The indoor environment is usually more polluted than outdoors due to emissions of gas and particle-phase pollutants from multiple sources, leading to their accumulation on top of the infiltration of outdoor pollution. While it is widely recognized that negative health effects arise from [...] Read more.

The indoor environment is usually more polluted than outdoors due to emissions of gas and particle-phase pollutants from multiple sources, leading to their accumulation on top of the infiltration of outdoor pollution. While it is widely recognized that negative health effects arise from the exposure to outdoor air pollution, exposure to indoor pollutants also needs to be well assessed since we spend most of our time (~90%) breathing indoors. Indoor concentrations of pollutants are driven by physicochemical processes and chemical transformations taking place indoors, acting as sources and/or sinks. While these basic concepts are understood, assessing the contribution of each process is still challenging. In this study, we deployed online instrumentation in an unoccupied room to test a methodology for the apportionment of indoor and outdoor pollutant sources. This method was successfully applied to the apportionment of PM₁ and VOCs, however, there are limitations for reactive gases such as O₃. The results showed that this unoccupied indoor environment acts as a source of VOCs and contributes 87% on OVOCs and 6% on C_xH_y, while it acts as a sink for particles, likely due to losses through volatilization up to 60%. Full article

(This article belongs to the Special Issue Innovative Air Pollution Measurements, Characterization and Source Apportionment)

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12 pages, 1545 KiB

Open AccessArticle

Indoor Carbon Dioxide, Fine Particulate Matter and Total Volatile Organic Compounds in Private Healthcare and Elderly Care Facilities

by Alexandre Baudet, Estelle Baurès, Olivier Blanchard, Pierre Le Cann, Jean-Pierre Gangneux and Arnaud Florentin

Toxics 2022, 10(3), 136; https://doi.org/10.3390/toxics10030136 - 12 Mar 2022

Cited by 25 | Viewed by 3909

Abstract

Poor indoor air quality can have adverse effects on human health, especially in susceptible populations. The aim of this study was to measure the concentrations of dioxide carbon (CO₂), fine particulate matter (PM_2.5) and total volatile organic compounds (TVOCs) [...] Read more.

Poor indoor air quality can have adverse effects on human health, especially in susceptible populations. The aim of this study was to measure the concentrations of dioxide carbon (CO₂), fine particulate matter (PM_2.5) and total volatile organic compounds (TVOCs) in situ in private healthcare and elderly care facilities. These pollutants were continuously measured in two rooms of six private healthcare facilities (general practitioner’s offices, dental offices and pharmacies) and four elderly care facilities (nursing homes) in two French urban areas during two seasons: summer and winter. The mean CO₂ concentrations ranged from 764 ± 443 ppm in dental offices to 624 ± 198 ppm in elderly care facilities. The mean PM_2.5 concentrations ranged from 13.4 ± 14.4 µg/m³ in dental offices to 5.7 ± 4.8 µg/m³ in general practitioner offices. The mean TVOC concentrations ranged from 700 ± 641 ppb in dental offices to 143 ± 239 ppb in general practitioner offices. Dental offices presented higher levels of indoor air pollutants, associated with the dental activities. Increasing the ventilation of these facilities by opening a window is probably an appropriate method for reducing pollutant concentrations and maintaining good indoor air quality. Full article

(This article belongs to the Special Issue Innovative Air Pollution Measurements, Characterization and Source Apportionment)

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16 pages, 7752 KiB

Open AccessArticle

Seasonality of Aerosol Sources Calls for Distinct Air Quality Mitigation Strategies

by Chunshui Lin, Darius Ceburnis, Colin O’Dowd and Jurgita Ovadnevaite

Toxics 2022, 10(3), 121; https://doi.org/10.3390/toxics10030121 - 3 Mar 2022

Cited by 3 | Viewed by 2903

Abstract

An Aerosol Chemical Speciation Monitor (ACSM) was deployed to investigate the temporal variability of non-refractory particulate matter (NR-PM₁) in the coastal city of Galway, Ireland, from February to July 2016. Source apportionment of the organic aerosol (OA) was performed using the [...] Read more.

An Aerosol Chemical Speciation Monitor (ACSM) was deployed to investigate the temporal variability of non-refractory particulate matter (NR-PM₁) in the coastal city of Galway, Ireland, from February to July 2016. Source apportionment of the organic aerosol (OA) was performed using the newly developed rolling PMF strategy and was compared with the conventional seasonal PMF. Primary OA (POA) factors apportioned by rolling and seasonal PMF were similar. POA factors of hydrocarbon-like OA (HOA), peat, wood, and coal were associated with domestic heating, and with an increased contribution to the OA mass in winter. Even in summer, sporadic heating events occurred with similar diurnal patterns to that in winter. Two oxygenated OA (OOA) factors were resolved, including more-oxygenated OOA and less-oxygenated OOA (i.e., MO-OOA and LO-OOA, accordingly) which were found to be the dominant OA factors during summer. On average, MO-OOA accounted for 62% of OA and was associated with long-range transport in summer. In summer, compared to rolling PMF, the conventional seasonal PMF over-estimated LO-OOA by nearly 100% while it underestimated MO-OOA by 30%. The results from this study show residential heating and long-range transport alternately dominate the submicron aerosol concentrations in this coastal city, requiring different mitigation strategies in different seasons. Full article

(This article belongs to the Special Issue Innovative Air Pollution Measurements, Characterization and Source Apportionment)

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19 pages, 3702 KiB

Open AccessArticle

Source Apportionment of Atmospheric PM₁₀ in Makkah Saudi Arabia by Modelling Its Ion and Trace Element Contents with Positive Matrix Factorization and Generalised Additive Model

by Turki M. Habeebullah, Said Munir, Jahan Zeb and Essam A. Morsy

Toxics 2022, 10(3), 119; https://doi.org/10.3390/toxics10030119 - 2 Mar 2022

Cited by 7 | Viewed by 3069

Abstract

In this paper, the emission sources of PM₁₀ are characterised by analysing its trace elements (TE) and ions contents. PM₁₀ samples were collected for a year (2019–2020) at five sites and analysed. PM₁₀ speciated data were analysed using graphical visualization, [...] Read more.

In this paper, the emission sources of PM₁₀ are characterised by analysing its trace elements (TE) and ions contents. PM₁₀ samples were collected for a year (2019–2020) at five sites and analysed. PM₁₀ speciated data were analysed using graphical visualization, correlation analysis, generalised additive model (GAM), and positive matrix factorization (PMF). Annual average PM₁₀ concentrations (µg/m³) were 304.68 ± 155.56 at Aziziyah, 219.59 ± 87.29 at Misfalah, 173.90 ± 103.08 at Abdeyah, 168.81 ± 82.50 at Askan, and 157.60 ± 80.10 at Sanaiyah in Makkah, which exceeded WHO (15 µg/m³), USEPA (50 µg/m³), and the Saudi Arabia national (80 µg/m³) annual air quality standards. A GAM model was developed using PM₁₀ as a response and ions and TEs as predictors. Among the predictors Mg, Ca, Cr, Al, and Pb were highly significant (p < 0.01), Se, Cl, and NO₂ were significant (p < 0.05), and PO₄ and SO₄ were significant (p < 0.1). The model showed R-squared (adj) 0.85 and deviance explained 88.1%. PMF identified four main emission sources of PM₁₀ in Makkah: (1) Road traffic emissions (explained 51% variance); (2) Industrial emissions and mineral dust (explained 27.5% variance); (3) Restaurant and dwelling emissions (explained 13.6% variance); and (4) Fossil fuel combustion (explained 7.9% variance). Full article

(This article belongs to the Special Issue Innovative Air Pollution Measurements, Characterization and Source Apportionment)

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16 pages, 2477 KiB

Open AccessArticle

Personal Exposure to Black Carbon, Particulate Matter and Nitrogen Dioxide in the Paris Region Measured by Portable Sensors Worn by Volunteers

by Baptiste Languille, Valérie Gros, Bonnaire Nicolas, Cécile Honoré, Anne Kaufmann and Karine Zeitouni

Toxics 2022, 10(1), 33; https://doi.org/10.3390/toxics10010033 - 11 Jan 2022

Cited by 9 | Viewed by 3100

Abstract

Portable sensors have emerged as a promising solution for personal exposure (PE) measurement. For the first time in Île-de-France, PE to black carbon (BC), particulate matter (PM), and nitrogen dioxide (NO₂) was quantified based on three field campaigns involving 37 volunteers [...] Read more.

Portable sensors have emerged as a promising solution for personal exposure (PE) measurement. For the first time in Île-de-France, PE to black carbon (BC), particulate matter (PM), and nitrogen dioxide (NO₂) was quantified based on three field campaigns involving 37 volunteers from the general public wearing the sensors all day long for a week. This successful deployment demonstrated its ability to quantify PE on a large scale, in various environments (from dense urban to suburban, indoor and outdoor) and in all seasons. The impact of the visited environments was investigated. The proximity to road traffic (for BC and NO₂), as well as cooking activities and tobacco smoke (for PM), made significant contributions to total exposure (up to 34%, 26%, and 44%, respectively), even though the time spent in these environments was short. Finally, even if ambient outdoor levels played a role in PE, the prominent impact of the different environments suggests that traditional ambient monitoring stations is not a proper surrogate for PE quantification. Full article

(This article belongs to the Special Issue Innovative Air Pollution Measurements, Characterization and Source Apportionment)

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